The biggest winner of the Trump presidency is also the most surprising: Federal Reserve Chairman Janet Yellen.

After all, Yellen was a constant target for criticism by Candidate Trump, going so far as to accuse her of being "more political than Hillary Clinton." Beyond Mr. Trump's barbed rhetoric, pundits such as Paul Krugman predicted that Trump's ascendency would be disastrous for the US economy and the stock market in general, which would have wiped out the modest recovery that Yellen's legacy depends on.

Almost a year after Trump's election, the world looks quite different. Not only has Wall Street toasted the Donald's victory, but the president continues to keep open the possibility of re-nominating Janet Yellen for a second term. Of course, given Trump's surprisingly strong understanding of how current Fed-policy was a positive for the administration, perhaps this reversal should have been as predictable as Paul Krugman being wrong.

For Yellen, more important than Trump's willingness to compliment her performance is what his presidency has done for the reputation of the Fed. Prior to this year, the Fed had been constantly forced to backtrack on planned interest rate hikes and downplay talk of balance sheet normalization due to economic stagnation.

For example, in 2016 the Fed was only able to hit one of its projected four interest rate hikes during the year, and that one came after the market surged following Trump's election. Still, many traders were skeptical of the Fed's forecast of three interest rate hikes.  Earlier in the year, Yellen was even forced to admit that forward guidance, a communication tool that was favored by Ben Bernanke, no longer worked because people simply stopped taking the Fed's projections seriously.